Norway hit by more ISA cases

ISA is suspected at a site run by Norway Royal Salmon

TWO more suspected outbreaks of Infectious Salmon Anaemia (ISA) have been reported at fish farms in northern Norway, bringing the total cases to at least five since May.

The first of the latest incidents is at Kleiva Fiskefarm and Gratanglaks AS in Troms and Finnmark county. The Norwegian Food Safety Authority said it plans an early inspection in the facility to carry out follow-up tests in order for the Veterinary Institute to be able to confirm that it is ISA. As with most cases involving ISA, the authority may order the cages to be emptied and the fish slaughtered if confirmed.

The second suspected outbreak is at three sites, also in the Finnmark region, operated by Norway Royal Salmon (NRS). The suspicion follows the results from various tests carried out by the Pathogen and Veterinary Institute after sampling fish at the sites. NRS, which is licensed to farm 35,000 metric tonnes of salmon in Troms and Finnmark, said it was awaiting confirmation or otherwise from the tests, adding that it was difficult to calculate the cost of such an outbreak. It is reported to have more than two million fish breeding in this area.

Last week the Food Safety Authority ordered the slaughter of 750,000 one kilo salmon at a Salaks company site south of Tromso after ISA was confirmed, which could cost the company up to NOK 45 million. The authority is also investigating a suspected case at a farm owned by Cermaq in Troms.

So far no-one is linking the incidents, but the fact most are happening in the same region will concern the authorities. ISA was first reported in Norway in 1984 but has since been found in most northern salmon farming countries including Canada, the USA, Scotland and Ireland. A major outbreak in Scotland in 1998-9 was successfully dealt with.

The greatest threat is to sea water farms but the highest risk factors include the movement of live fish and contact with infected vehicles and equipment. At the moment there is no effective treatment for the disease. While not harmful to humans, it is highly contagious among farmed salmon.